Cryogenically treated drilling and mining equipment

ABSTRACT

The thermally treated piece of drilling equipment is made by placing a device within a thermal control apparatus and subjecting the device to two thermal cycles. The first thermal cycles involves introducing a cryogenic material into the thermal control apparatus decreasing the device temperature, while preventing over-stressing of the device, to a first target temperature at a first temperature rate. The device temperature is then increased to a second target temperature at a second temperature rate. The second thermal cycle involves introducing the cryogenic material to decrease the device temperature, while preventing over-stressing, to a third temperature at a third temperature rate ranging. The temperature is then increased to a fourth temperature at a fourth temperature rate. The result of the process is a piece of drilling equipment without fractures and enhanced structural characteristics.

The present application claims priority to co-pending U.S. ProvisionalPatent Application Ser. No. 60/511,502 filed on Oct. 14, 2003.

FIELD

The present embodiments relate to drilling or mining equipment treatedby a thermal process to improve the structural characteristics of theequipment.

BACKGROUND

A need exists for a process to treat equipment and similar devices ofmanufacture in order to increase their structural characteristics. Forexample, in the manufacture of drilling equipment, tools and toolcomponents, machinery, engine parts, wear surfaces, bearings, and likearticles from various steels and materials that are used for high wearapplications.

A number of thermal type processes are known in the metallurgical artsto enhance the properties of manufacturing materials, such as steels andthe like. One widely used class of such metallurgical processesgenerally known as quenching typically involves forming an article ofthe desired metal containing material and then rapidly lowering thetemperature of the article followed by a return of the article toambient temperature. The problem with the current processes is that theyare usually uncontrolled and result in over-stressing the material andeven fracturing the material rendering it useless.

A further enhancement process for manufacturing materials, such assteel, is in the formation of a nitride containing layer on the surfaceof an article of the metal containing material that case hardens thematerial by forming nitrides such as metal nitrides at or near thesurface of an article. The formed nitride surface layer may includeextremely hard compounds containing nitrides such as CrN, Fe₂N, Fe₃N andFe₄N. The formed nitride layer tends to create compressive stresses thatimprove the properties of the metal containing material, but can alsolead to distortions in the article being treated.

A need has long existed for drilling and mining equipment that isstronger, less brittle and tougher than current equipment.

A process has long been needed to provide improved drilling, mining,earth moving, and subsea working equipment.

SUMMARY

The piece of drilling equipment is created by placing the piece ofdrilling equipment is made by placing the equipment within a thermalcontrol apparatus. The thermal control apparatus has a chamber, whereinthe chamber temperature is closely regulated. A first cryogenic materialis introduced into the thermal control apparatus decreasing the devicetemperature while preventing over-stressing of the device. Thetemperature of the device is reduced to a first target temperatureranging from −40 degrees F. and −380 degrees F. at a first temperaturerate ranging from 0.25 degrees F. per minute and 20 degrees F. perminute. When the first target temperature is reached, the cryogenicmaterial is no longer introduced into the chamber. The chambertemperature is, then, increased to a second target temperature rangingfrom 0 degrees F. and 1400 degrees F. at a second temperature rateranging from 0.25 degrees F. per minute and 20 degrees F. per minute.The first cycle results in an intermediate device.

The second cycle begins by introducing a second cryogenic material intothe thermal control apparatus decreasing the temperature of theintermediate device while preventing over-stressing. The temperature isdecreased to a third target temperature ranging from −40 degrees F. and−380 degrees F. at a third temperature rate ranging from 0.25 degrees F.per minute and 20 degrees F. per minute. When the second targettemperature is reached, the cryogenic material is no longer introducedinto the chamber. The temperature of the chamber is increased to afourth target temperature from 0 degrees F. and 1400 degrees F. at afourth temperature rate ranging from 0.25 degrees F. per minute and 20degrees F. per minute. The result of the process is a piece of drillingequipment without fractures and enhanced structural characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

The present piece of drilling equipment will be explained in greaterdetail with reference to the appended Figures, in which:

FIG. 1 is a diagram of the steps of the method for treating drilling andmining equipment;

FIG. 2 depicts a cross section of the chamber used in the process; and

FIG. 3 is a diagram of the steps of producing a thermally treated deviceby a thermal process using three thermal cycles.

The present piece of drilling equipment is detailed below with referenceto the listed Figures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before explaining the present piece of drilling equipment in detail, itis to be understood that the piece of drilling equipment is not limitedto the particular embodiments herein and it can be practiced or carriedout in various ways.

An embodiment relates to various types of drilling and mining equipmentincluding drill bits that are cryogenically treated, inserts for use inroller cone drill bits, mining equipment, and earth moving equipment.

An embodiment also relates to the production of equipment used indrilling and mining operations.

FIG. 1 provides the steps of producing drilling equipment by a thermalprocess. The first step involves placing a device such as a drill bit,or pump, into a thermal control apparatus (110).

FIG. 2 depicts a cross sectional view of the thermal control apparatus(12) that comprises a chamber (14). The device (10) is placed within thechamber (14). In the embodiment of FIG. 2, cryogenic material (18) isintroduced to the thermal control apparatus (12), such as through avalve (26) such that the temperature of the chamber (14) increases ordeceases depending on whether the valve (26) is on or off. Thetemperature of the chamber (14) is closely regulated.

The thermal control apparatus (12) can further include a heat exchanger(16) located within the chamber (14) to provide a cryogenic vapor (20)to the chamber (14). The cryogenic material (18) is released into theheat exchanger (16) thereby absorbing heat from the chamber (14) intothe heat exchanger (16) forming a cryogenic vapor (20) that fills thechamber (14). Examples of cryogenic vapors contemplated in thisinvention are hydrogen, nitrogen, oxygen, helium, argon, andcombinations thereof.

The chamber used in the thermal process can be a double-walled insulatedchamber, a vacuum chamber, and a vacuum-insulated chamber. Computercontrol (22) of the cryogenic process consists of a dedicatedmicroprocessor unit (24) that controls injection of the cryogenicmaterial (18) via a solenoid-operated valve (26).

Thermocouples (28 a and 28 b) provide real-time temperature measurement,and feedback to the microprocessor (24), which then follows theprogrammed temperature targets and rates.

Continuing with FIG. 1, a first cryogenic material in introduced todecrease the material temperature of the device material whilepreventing the overstressing of the device (120). In a preferredembodiment, the cryogenic material is used to decrease the devicetemperature to a first target temperature that ranges from −40° F. to−380° F. at a temperature rate of change ranging from 0.25° F. perminute to 20° F. per minute (130).

The device can be drill bits, bearings, pumps, engines, drill stem,casing, borers, grinders, bucket teeth, hammers, grinders, cuttingteeth, actuators, and combinations of these devices. In addition, thedevice can be any device that experiences wear and tear during anymining process.

The device can also be any device that is used to move earth material inassociation with mining and drilling operations. As an optional nextstep, once the device reaches the first target temperature, the devicecan soak at this first target temperature for a period of time rangingfrom 15 minutes to 96 hours. The range can optionally range from 1minute to 15 minutes and for periods of time from 96 hours to 180 hours.

Returning to FIG. 1, the method continues by stopping the introductionof the cryogenic material into the chamber once the first targettemperature is reached (140). The chamber temperature is then increasedto a second target temperature ranging from 0 degrees F. to 1400 degreesF. (150). The device temperature is also increased to the second targettemperature at a second temperature rate (160). The second temperaturerate ranges from 0.25 degrees F. per minute to 20 degrees F. per minute.The result is an intermediate device with an intermediate devicetemperature (170).

Optionally, the intermediate device can be permitted to soak at thesecond target temperature for a period of time that ranges from 15minutes to 48 hours. The soaking at the second temperature can vary fromless than 15 minutes to about 1 minute and up to 2 weeks. The preferredaging process at the elevated temperature may be as short as 4 days torelieve the stress in the device.

Continuing with FIG. 1, a second cryogenic material, which may differfrom the first cryogenic material, is introduced into the thermalcontrol apparatus decreasing the intermediate device temperature whilepreventing over-stressing of the intermediate device (220). Thetemperature is reduced to a third target temperature ranging from −40degrees F. to −380 degrees F. at a third temperature rate ranging from0.25 degrees F. per minute to 20 degrees F. per minute (230). The methodcontinues by stopping the introduction of the cryogenic material intothe chamber once the third target temperature is reached (240).

The chamber temperature is, then, increased to a fourth targettemperature ranging from 0 degrees F. to 1400 degrees F. (250). Theintermediate device temperature is, thereby, also increased to thefourth target temperature at a fourth temperature rate (260). The fourthtemperature rate ranges from 0.25 degrees F. per minute to 20 degrees F.per minute. The result is a piece of drilling equipment, withoutfractures and enhanced structural characteristics (270).

The treated device without fractures can be used in the intendedpurpose, and as parts of other earth moving equipment, such as backhoes, loaders, pumps, cutters and saws.

In one embodiment, the device can be treated using a first temperaturerate and a second temperature rate that are substantially the same.Alternatively, the method will work if all temperature rates aredifferent within the assigned ranges.

In an alternative embodiment, the device can be further treated by athird cycle. FIG. 3 depicts steps of producing a thermally treateddevice using three thermal cycles the process resulting in a treateddevice without fractures and improved structural and metallurgicalcharacteristics. More than three cycles can be applied to the device.

In the third cycle, the cryogenic material is added to the thermalcontrol apparatus to decrease the device temperature while preventingover-stressing of the device (320). The device temperature is reduced toa fifth target temperature ranging from −40 degrees F. to −380 degreesF. at a fifth temperature rate (330). The fifth temperature rate rangesfrom 0.25 degrees F. per minute to 20 degrees F. per minute. When thefifth target temperature is reached, the cryogenic material is no longerintroduced into the chamber (340).

The third cycle continues by increasing the chamber temperature to asixth target temperature and, thereby, increasing the device temperatureto the sixth target temperature ranging from 0 degrees F. to 1400degrees F. (350). The temperature increase is done at a sixthtemperature rate ranging from 0.25 degrees F. per minute to 20 degreesF. per minute (360) resulting in a piece of drilling equipment, withoutfractures and enhanced structural characteristics (270).

The treated device described can be used for drilling bits and miningequipment, as well as for swords and metals needed for extremetemperatures, such at high subsea pressures. The treated device can alsobe used in the extremes of high altitude, such as, in airplanes, jets,on satellites and other materials used in space.

In another embodiment, the first temperature rate is used to create oneor more of a set of desired metallurgical characteristics in the treateddevice. For example, the first temperature rate can cause improved wearresistance and the second temperature rate can cause improved impactresistance. Alternatively, the metallurgical characteristics can behardness, strength, and combinations of these properties.

Overstressing within the context of this application refers to the actof causing fractures in the device or treated device material. Thepresent method is designed to treat the device without causing fracturesand related stress defects in the material while causing otheradvantageous metallurgical characteristics.

The method used to treat the device of the drilling equipment can have afirst, second, third and fourth temperature rates which are determinedby the mass of the device.

The device can be a composite of many parts, such as pistons, rings,pumps, bearings, actuators, lifters, clamps cams, or combinationsthereof. The device of can be a part of a larger machine or device suchas an engine, transmission, or drilling rig. Alternately, the device canbe a stand alone tool dependent on no other for function.

While this piece of drilling equipment has been described with emphasison the preferred embodiments, it should be understood that within thescope of the appended claims the piece of drilling equipment might bepracticed other than as specifically described herein.

1. A piece of drilling equipment made by the steps comprising: a.placing a device having a device temperature within a thermal controlapparatus comprising a chamber comprising a chamber temperature; b.introducing a first cryogenic material into the thermal controlapparatus to decreasing the device temperature and while preventingover-stressing of the device, to a first target temperature ranging from−40 degrees F. to −380 degrees F. at a first temperature rate rangingfrom 0.25 degrees F. per minute to 20 degrees F. per minute; c. stoppingthe introduction of the cryogenic material into the chamber once thefirst target temperature is reached; d. increasing the chambertemperature to a second target temperature ranging from 0 degrees F. to1400 degrees F.; e. increasing the device temperature to the secondtarget temperature at a second temperature rate ranging from 0.25degrees F. per minute to 20 degrees F. per minute resulting in anintermediate device having an intermediate device temperature; f.introducing a second cryogenic material into the thermal controlapparatus to decreasing the intermediate device temperature whilepreventing over-stressing of the intermediate device, to a third targettemperature ranging from −40 degrees F. to −380 degrees F. at a thirdtemperature rate ranging from 0.25 degrees F. per minute to 20 degreesF. per minute; g. increasing the chamber temperature to a fourth targettemperature ranging from 0 degrees F. to 1400 degrees F.; and h. causingthe intermediate device temperature to increase to the fourth targettemperature at a fourth temperature rate ranging from 0.25 degrees F.per minute to 20 degrees F. per minute resulting in a treated devicewithout fractures.
 2. The drilling equipment of claim 1, wherein thedevice is selected from the group consisting of drill bits, pumps,engines, levers, actuator arms, bearings, cams, lifters, valves,engines, and combinations thereof.
 3. The drilling equipment of claim 1,wherein the first temperature rate is different from the secondtemperature rate to create a desired metallurgical characteristic in thetreated device, wherein the characteristic is selected from the groupconsisting of wear-resistance, impact resistance, ductility, hardness,strength and combinations thereof.
 4. The drilling equipment of claim 1,wherein the device is treating using a first temperature ratesubstantially the same as the second temperature rate.
 5. The drillingequipment of claim 1 wherein the intermediate device is treated furtherusing the steps of: a. introducing a third cryogenic material into thethermal control apparatus to decreasing the intermediate devicetemperature while preventing over-stressing of the intermediate device,to a fifth target temperature ranging from −40 degrees F. to −380degrees F. at a fifth temperature rate ranging from 0.25 degrees F. perminute to 20 degrees F. per minute; b. increasing the chambertemperature to a sixth target temperature from 0 degrees F. to 1400degrees F.; and c. increasing the intermediate device temperature to thesixth target temperature at a sixth temperature rate ranging from 0.25degrees F. per minute to 20 degrees F. per minute resulting in treateddevice without fractures.
 6. The drilling equipment of claim 1, furthercomprising the step of permitting the device to soak at the first targettemperature for a first period of time.
 7. The drilling equipment ofclaim 9, wherein the first period of time ranges from 15 minutes to 96hours.
 8. The drilling equipment of claim 1, further comprising the stepof permitting the intermediate device to soak at the second targettemperature for a second period of time that ranges from 15 minutes toup to 48 hours.
 9. The drilling equipment of claim 1, wherein thethermal control apparatus further comprises a heat exchanger.
 10. Thedrilling equipment of claim 1, wherein the cryogenic material is amember of the group consisting of hydrogen, nitrogen, oxygen, helium,argon, and combinations thereof.
 11. The drilling equipment of claim 1,wherein the first temperature rate, the second temperature rate, thethird temperature rate and the fourth temperature rate and aredetermined by the mass of the device.
 12. The drilling equipment ofclaim 1, wherein the device is used to drill, cut, shape, gouge, rasp,or abrade materials selected from the group consisting of wood, ceramic,metal, plastic, composite material, and combinations thereof.